Each fish in El-Fish has a unique Roe, similar to the genome. This allows the user to catch fish and use selective breeding and mutation to create fish to their own tastes for placing them in virtual aquariums. Around 800 possible genetic attributes (fin shape, body color, size, etc) are available, which can be selectively shaped into infinite numbers of unique fish. Once fish are created, El-Fish will algorithmically generate up to 256 animation frames so that the fish will appear to swim smoothly around the tank.
The tank simulator is very customizable for this game's era. The player can select from a large number of backdrops and tank ornaments for the fish to swim between. The user can also import their own images to use as tank ornaments. El-Fish includes a fractal based plant generator for creating unique aquarium plants. There are several "moving objects" that can be added to the tanks which the fish will react to, such as a cat paw, fibcrab, and a small plastic scuba diver. The user can also procedurally generate background music for their tank using an ingame composer, or choose a separate MIDI music file to be played for each virtual aquarium, and feed the fish.
El-Fish was developed by many bright minds, most with Ph.D.s, and some had worked on high profile projects such as the Russian space program.
Although El-Fish's demanding (for its time) system requirements prevented it from selling many units, it was an early version of what would become a very widespread genre.
|386SX16||5-7 minutes||6-7 hours|
|386DX25†||25-35 seconds||25-35 minutes|
|486DX33||7-10 seconds||7-10 minutes|
|486DX2-66||5 seconds||4-6 minutes|
The animating time of a fish depends heavily on its size, where a very small fish can be animated on a 386DX40 with 4MB of RAM in 2-4 hours, a very large fish can take easily up to 24+ hours.
The performance of the game itsself in the play mode varies depending how fast/slow the CPU is. The game in the Maxis version measures the speed of the CPU, so on a slow 386 it will only display 1-3 fish at once, but on a 486 it will show 10+ fish. This speed measurement will not work on modern PCs where the CPU speed went over the programs maximum and miscalculates the actual speed. For example the CPU is 3600MHz, but the program thinks your CPU is too slow and only will display 1-3 fish. This can be solved with several speed limitation software. It does not have to be slowed down to a 486's speed, but it has to fit the programs measurement calculation for displaying the maximum amount of fishes. This varies on the CPU speed. The first Mindscape version of the game does not have this mistake calculation.